"This date is reliable," Engelbert Luetke Daldrup told reporters after a meeting of the airport's state owners.

"With today's supervisory board meeting we will kick off the final phase towards completing the terminal and the opening of the airport."

The new international airport has called Germany's engineering prowess into question. The project has been beset by embarrassing delays caused by red tape, suspicions of bribery, plus a raft of technical problems, including issues with smoke ventilation systems, cabling, ceiling fans, and the doors.

A planned opening in June 2012 was called off with just three weeks' notice, leaving airlines scrambling to reorganise operations, and a series of tentative opening dates since then have come and gone, as have several CEOs.

The delays have also been partly blamed for the demise of Air Berlin, which wanted to use the new airport as a hub for more lucrative long-haul flight connections but filed for insolvency in August after years of losses.

Berlin is currently served by two former cold war airports - Tegel in the north west of Berlin and Schoenefeld to the south east of the city.

Adding to its woes, the new airport will be too small when it opens. Tegel and Schoenefeld served 33 million passengers last year, but the new hub is set for an initial capacity of 27 million.

Tegel, which is running at full capacity, is due to close once the new airport opens, but Berliners voted to keep it open in a non-binding referendum in September, posing a further headache for the state owners.

The new airport, named after the late politician Willy Brandt, is jointly owned by the federal government as well as the state governments of Berlin and Brandenburg.

(Reporting by Victoria Bryan. Editing by Andreas Cremer and David Evans)